Longview provided few details except that the prospective bidder would pay for the deal with its own shares.
The company says it has set up a special committee to review the proposal and also adopted a shareholder rights plan.
The rights plan is a defensive move to provide Longview's board with time to evaluate the offer and alternatives.
The overture comes at a time when Longview is preparing to become independent of its largest shareholder.
Advantage Oil & Gas Ltd. (TSX:AAV) said last week that it would sell its 45 per cent stake in Longview for $94.1 million by the end of February.
They also agreed to terminate a technical services agreement in which Advantage provided the personnel to manage Longview's business.